STEPPED HYDRAULIC DRIVE CONTROL DEVICE Russian patent published in 2002 - IPC

FIELD: hydraulic drives. SUBSTANCE: proposed device has consumer, first and second distributors, each being connected in parallel to consumer by supply hydraulic line, and pressure hydraulic line and drain hydraulic line connected to both distributors. One of supply hydraulic lines communicates with pressure hydraulic line through one of distributors when consumer is in upper extended position, and first and second distributors are coupled by additional hydraulic line connected also to input of one of supply hydraulic lines. Other supply hydraulic line is connected with pressure hydraulic line through both distributors when consumer is in upper extended position. EFFECT: improved reliability. 2 cl, 4 dwg